<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      body,
      ul {
        margin: 0;
        padding: 0;
      }
      body {
        width: 100%;
        height: 100%;
        background-image: url(../images/grid.png);
      }
      svg {
        background-color: rgba(255, 0, 0, 0.1);
      }
      text {
        /* fill: red; */
        /* stroke: red; */
      }
    </style>
  </head>
  <body>
    <!-- svg 2.0用法 -->
    <svg width="300" height="300">
      <!-- 
        g 元素没专有的属性，只有全局的属性
          全局属性id，class，style，fill，stroke，onclick
       -->
      <g fill="transparent" stroke="red">
        <circle cx="50" cy="50" r="25"></circle>
        <circle cx="80" cy="50" r="25"></circle>
        <circle cx="110" cy="50" r="25"></circle>
        <circle cx="140" cy="50" r="25"></circle>
      </g>
    </svg>
  </body>
</html>
